(1) Field of the Invention
The present invention relates generally to universal joint socket wrenches and, more particularly, to a device for providing self-alignment of the wrench with the nut or bolt to be turned.
(2) Description of the Prior Art
The popularity of the simple universal joint socket wrench is due to its strength, compactness in size, and cost of its basic construction. However, the repeated use of the wrench results in worn mating surfaces of the universal joint. As this condition progresses the socket end of the wrench becomes increasingly difficult to align and attach to a nut or bolt. The problem is due to lateral forces applied to the universal joint by accidentally bumping the socket end against objects surrounding the linear path between the repair person and the nut or bolt to be turned as well as the gravitational pull on the socket.
Some different designs of universal joint type wrenches have provided a means of self-alignment. For example, the following patents related to universal joints employ a spring biasing principle to align the wrench: U.S Pat. No. 1,324,898 issued to Hopcraft; U.S. Pat. No. 1,975,695 issued to Lund; U.S. Pat. No. 2,499,569 issued to Cooley; and U.S. Pat. No. 4,065,941 issued to Aoki.
However, the majority of universal joint designs only provide means for universal movement without a means for self-alignment. Thus, various other approaches to this problem include replacing the worn universal joint with a new one, accepting the problem and living with it, or wrapping a length of electrical tape around the body of the universal joint for added support. While the electrical tape method works, it introduces other problems. For example, the adhesive in the electrical tape attracts dust and dirt, any contact with oil or solvents causes the tape to slowly detach from the universal joint, and the lifetime of the resilience response of the tape is short.
A solution to a somewhat related problem is illustrated in U.S. Pat. No. 4,530,261 issued to Ventura. The Ventura patent discloses a wrench adapted for tightening mine wall support bolts. The wrench includes a resilient, impermeable sleeve which surrounds the universal joint. The sleeve is specially designed with sufficient thickness and a high enough material density to limit the movement of the universal joint. In addition, the sleeve also seals the joint against the infusion of solid and liquid matter. However, there is no recognition by Ventura of the problem of worn mating align and attach to a nut or bolt. Furthermore, the sleeve, as taught by Ventura, is held in place by an outer clamp and can not be readily removed without tools.
Thus, there remains a need for an alignment sleeve for a hand tool having a universal joint which is adapted for quick installation and removal by hand, is self-securing, does not collect dust and dirt, is unaffected by oil or solvents, and retains its resiliency over time.